Artículos científicos
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Nuevo enfoque combinatorio para el problema del paseo al azar en un espacio n-Dimensional
(Universidad Nacional (Costa Rica), 1994)Se presenta un nuevo enfoque combinatorio para resolver el problema del cálculo de las probabilidades de paso –probabilidades de transición entre dos posiciones cualesquiera- de una partícula que se desplaza siguiendo una ... -
Image and dosimetry quality control for digital mammography by using the Normi Mam Digital phantom
(Universidad Nacional, Costa Rica, 2018-07-26)In Costa Rica there is not an explicit recommendation given by the Regulatory Authorities for the utilization of a specific Phantom; that is why experts have to explore what is offered in the market. One of the most ... -
Estimación de la radiación solar global incidente en superficies inclinadas
(Universidad Nacional, Costa Rica, 1992-01-01)Se estimaron valores diarios medios mensuales de la radiación solar global incidente sobre un colector solar inclinado, orientado hacia el sur, con datos observados o estimados de la radiación solar global, directa o ... -
Correlación entre la radiación solar global y el número de días con precipitación pluvial
(Universidad Nacional [Costa Rica], 1989-01-01)Este trabajo mide el grado de asociación entre datos experimentales de radiación solar global y número de días con precipitación en diez localidades de Costa Rica; con el objetivo de establecer relaciones para la estimación ... -
Influence of substrate temperature on phase formation in Al-Cr thin films
(Universidad Nacional, Costa Rica, 2000)Thin films (of the order of nm) of Al-Cr alloys were prepared by successive depositions by an electron gun in a vacuum chamber. Three Al and two Cr layers, of thicknesses as to yield the final composition, were de posited ... -
Propositional calculus and binary calculus
(Universidad Nacional [Costa Rica], 1990-01-01)We present an efficient method of propositional calculus which allows the manipulation of logical functions with an arbitrary number of propositional variables. This method is base on the use of binary sequences (in other ... -
M2 Currents And Residual Flow In The Gulf Of California
(Elsevier, 1992)The full nonlinear, vertically-averaged equations of motion are time integrated through a finite difference scheme on a regular grid that reproduces the topography of the Gulf of Califor nia with a mesh size of 14 ... -
Experimental And Theoretical Analysis Of A Simple Solar Oven In The Climate Of Costa Rica - I
(Elsevier, 1988)Inexpensive and easy to fabricate solar ovens have been made with available materials. One reflector has also been mounted to increase the input radiation on the hot absorbing plate which can be adjusted manually according ... -
Líneas ciclotrónicas en el espectro de rayos y pulsado
(Universidad Nacional [Costa Rica], 1989-01-01)Si el proceso de Bremsstrahlung magnético es el responsable de las líneas observadas en los espectros de dos estallidos de rayos y, GB880205 y GB870303 detectados por el espectrómetro del satélite GINGA, entonces los ... -
La radiación de frenado en campos magnéticos fuertes
(Universidad Nacional [Costa Rica], 1989-01-01)Presentamos un análisis de las funciones de transición de Bremsstrahlung en función de la polarización de espín total del electrón a lo largo del campo magnético externo y la polarización lineal o circular de la radiación ... -
Feasibility of dose enhancement assessment: preliminary results by means of Gd-infused polymer gel dosimeter and Monte Carlo study
(Universidad Nacional (Costa Rica), 2018)This work reports the experimental development of an integral Gd-infused dosimeter suitable for Gd dose enhancement assessment along with Monte Carlo simulations applied to determine the dose enhancement by radioactive ... -
Effectiveness of N-waves for predicting morphological changes due to tsunamis
(Elsevier, 2018)The research on morphological changes caused by tsunamis has increased considerably in the last few years, yet the processes behind this phenomenon are still not fully understood. This paper analyzes and compares numerical ... -
Economic Analysis Of Domestic Solar Still In The Climate Of Costa Rica
(Universidad Nacional (Costa Rica), 1990)-In many communities of the developing countries, including Costa Rica and especially in coastal areas, there exists a shortage of potable water. Taking into account the fact that transportation/distribution of potable ... -
Comparative Study Of Conventional And Sbci Cardboard Solar Ovens
(Elsevier, 1992)Two folding and light solar ovens designed and constructed by Solar Box Cookers International (SBCI), Sacramento, U.S.A., have been studied experimentally. Furthermore, their performance is com pared with standard two ... -
Dairy wastewater treatment by anaerobic fixed bed reactors from laboratory to pilot-scale plant: A case study in Costa Rica operating at ambient temperature
(Springer, 2013)The effect of hydraulic retention time in a range from 1.0-5.5 days was evaluated in a laboratory scale anaerobic fixed bed reactor packed with a hybrid material composed of tire rubber and zeolite. Under these conditions, ... -
Design, construction and experimental study of electric cum solar oven-II
(1989)As in many developing countries,35-401 of the population of Costa Rica still use firewood for domestic cooking.Considering the fact that Costa Rica is blessed with good sunshine,good hydroelectric potential,and there ... -
Design, construction and study of a hybrid solar food processor in the climate of Costa Rica
(Elsevier, 2007)During the last 25 years, the author has designed, constructed, studied and promoted solar oven, hybrid solar/electric oven, solar oven cum drier, solar cooker cum water heater and solar still. In different parts of the ... -
An evaluation of variables affecting the stability and performance of down-flow anaerobic fixed bed reactors treating piggery wastewater
(Taylor & Francis, 2006)The influence of the most important variables on the stability and performance of down-flow anaerobic fixed bed reactors treating piggery wastewater after primary sedimentation was evaluated at HRT in the range of 1-6 d ... -
High Specific Capacity of Lithium–Sulfur Batteries with Carbon Black/Chitosan- and Carbon Black/Polyvinylidene Fluoride-Coated Separators
(MDPI, 2022-03-17)In this research, the shuttle effect and the low sulfur activation of lithium–sulfur batteries were mitigated by coating the cathode side of Celgard 2400 separators with mixtures of carbon black/chitosan or carbon ... -
Aplicaciones del modelo de Barbaro et al. para el cálculo de la radiación solar global por medio de estimaciones de los componentes directos y difusos, en Limón y Puntarenas, Costa Rica, para el período 1970-1972
(Universidad Nacional (Costa Rica), 1987-01-01)El presente trabajo utiliza un modelo atmosférico propuesto por Barbaro et al., para el cómputo de la radiación solar global a través de las estimaciones de las componentes directa y difusa, en Limón y Puntarenas, Costa ...
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